It seems to me that it would be far simpler if the spice blend could just be listed by its name in the ingredient list of each recipe where it is used, and if that ingredient would also appear as a link to the recipe for the spice blend. So for example, in The Soul of a New Cuisine, "berbere" would appear as an ingredient for the rack of lamb, and for the doro wett, and in each case would appear as a link. That way, any user could easily see that it is a sub-recipe, and click on it to see the additional ingredients listed. It would solve the problem of finding more recipes that use the spice blend, because now the search feature would work and one could just search within the book for that "ingredient". Plus, it would make indexing easier, as all those ingredients would not need to be typed out multiple times.
Having that long list of ingredients for the spice blend listed in the main recipe is really not as helpful as it would be to have the spice blend shown by name with a link to its ingredients. The reason is that I may not recognize all those ingredients as being berbere, or whatever the blend in question is, and shy away from making the recipe because I already used up the last of my cardamom making berbere for the lamb!
A ingredient that is a sub-recipe shown as a link would solve that problem, and also be very intuitive for users who do not have the blend already made up. A link would be pretty obvious as indicating something you need to click on for more information.